A study coordinated by the Mediterranean Agroforestal Institute (AMI), the Universidad Politécnica de Valencia (UPV), has found that soil predatory mites are a perfect ally against thrips infestation in citrus.
As the center reported to the press, the research has been developed in collaboration with the University of Navarra and the Belgian company Biobest, Belgium. This investigation was recently published in the journal Biological Control.
UPV researchers studied the fauna in the soil and its impact on presence or absence of the pest, a research hitherto unexplored.
Four citrus orchards located in Valencia were analyzed, in which fifteen species of
eight families of mites were identified.
The results obtained from the tests done in the field and laboratory showed that the mite could act better against the plague when it is one of the most abundant species in the ground (Gaeolaelaps aculeifer).
"The study concluded that there is a direct relationship between the increased presence of this mite on earth and lower numbers of thrips in the citrus," stressed AMI investigator Ferran Garcia, so these insects could be an alternative to chemicals that are currently used.
Garcia recalled that the thrips infestation caused by the insect Pezothrips kellyanus, causes a round scar on top of the fruit, and although it is a "merely cosmetic" condition, it has serious economic consequences, since it prevents the export of the affected citrus.
Moreover, scientists conducted various tests to determine whether the application of insecticides on leaves or adding organic matter to soil affects the abundance of predators in the soil.
The conclusion was that those lands to which they have added more manure has more predatory mites, while the treatment with chlorpyrifos pesticide does not affect their abundance, as explained Cristina Navarro, AMI investigator.